JP4798961B2 - HEATER DEVICE AND GAS SENSOR DEVICE USING THE SAME - Google Patents

Description

  The present invention uses a four-terminal method to measure the temperature of a specific region where the temperature of a thin film temperature sensor made of a temperature-sensitive resistor is uniform, and to control the temperature so that the heater device has high reliability and stability. The present invention relates to a gas sensor device using the same.

  Currently, heater devices such as a temperature sensor, a humidity sensor, a gas sensor, and a flow rate sensor are put into practical use. In such a heater device, a thin film heater or a thin film temperature sensor made of a temperature sensitive resistor is generally formed on the surface of an insulated substrate, and the thin film on which the thin film heater or the thin film temperature sensor is formed is used. The exothermic part is formed in the substrate with a cavity that opens on both sides and communicates with the back side. In such a heater device, the heat-generating part is thermally separated from the substrate by a cavity, and the heat capacity of the heat-generating part is reduced in a suspended state, thereby improving sensitivity and responsiveness. , A flow sensor, a humidity sensor, a gas sensor, and a temperature sensor ”(see Patent Document 1).

  Such a heater device is generally formed of a platinum-based thin film heater. When a constant energy is supplied by electric power and self-heating is performed, heat is dissipated by heat conduction according to various environments, and a constant resistance value is obtained. In other words, there is a proposal such as “atmosphere sensor structure” that enables detection of temperature, absolute humidity, gas flow velocity, and the like (see Patent Document 2).

  In the conventional “atmosphere sensor structure” technology according to Patent Document 2, high sensitivity, a high response speed, and a short temperature increase / decrease time are required. For this reason, heat is likely to be released in the vicinity of the support portion of the heat generating portion or in the outer peripheral portion of the thin film heater, so that there is a problem that the temperature at those locations decreases and the thin film heater has a temperature distribution.

  Moreover, it has already been demonstrated to obtain the temperature distribution of the thin film heater using a flow sensor (see Non-Patent Document 1).

  In addition, as a heater device that detects and measures gas components such as hydrogen, oxygen monoxide, methane, and propane, a gas-sensitive material thin film is generally formed on or under a pair of platinum-based gas-sensitive detection electrodes. In addition, by contacting with various gas components, the electric resistance of the gas-sensitive material thin film is changed to inform the types and concentrations of various gas components. These changes in electrical resistance need to be detected by heating to a high temperature of 200 ° C. to 500 ° C. in order to promote gas adsorption and reaction occurring on the gas sensitive material thin film. There are proposals such as "Sensor and humidity gas detection method" (see Patent Document 3).

JP-A-10-213470 JP-A-6-118046 JP 2003-279523 A JP 2000-266714 A J.J.van Baer, et. Al., "Sensitive thermal flow sensor based on a micro-machined two dimensional resistor array", TRANSDUCERS 2001 (The 11th International Conference on solid-State Sensors and Actuators)

  In the conventional “sensor and humidity gas detection method” according to Patent Document 4, the heat generating part is thermally separated from the substrate, the size of the thin film heater and the gas sensitive detection electrode are equal, and the thin film heater has temperature unevenness. In some cases, the gas sensitive detection electrode has a temperature difference, and gas sensitivity and selectivity cannot be sufficiently obtained.

  By the way, when the temperature change information is obtained by forming the thin film heater in a platinum system, it is desirable that a large output current is supplied to increase the sensitivity in order to improve sensitivity. However, with conventional thin film heaters, the temperature around the thin film floating in the air drops due to heat dissipation, and the temperature near the center is relatively high because heat is difficult to escape. Since the distribution increases as the Joule heat increases, when using it for a temperature sensor, etc., the average temperature of the thin film temperature with a large temperature distribution is needed to know the temperature near the center of the thin film with the highest sensitivity. There are problems such as temperature measurement. Further, since it is added to the resistance of the thin film heater that measures the platinum thin film on the beam that floats in the air and supports the thin film, there is a problem that accurate temperature measurement near the center of the thin film is difficult.

  In addition, a pair of platinum-based gas-sensitive detection electrodes are generally formed on a flat surface, and the gas-sensitive detection electrodes are arranged so as not to overlap with the heater section that is heated to a high temperature or a thick insulating layer. And flattening by installing between the heater. However, the gas sensitive detection electrode can be easily made uniform by flattening, but in order to improve the gas detection sensitivity, the gap between the gas sensitive detection electrodes is narrowed and the gas sensitive detection electrode is used. It is necessary to enlarge the area of

  Furthermore, in these heater devices, in order to ensure the resistance value necessary for the measurement, the thin film heater needs to have an elongated wiring shape. Since the detection location of the resistance value is the same, there is a problem that a temperature difference between the vicinity of the center and the outer periphery of the thin film heater and a resistance reaching the wiring are detected.

  In view of the above problems, the present invention obtains necessary information from temperature measurement only in the necessary uniform temperature region of the heat generating portion, thereby accurately and stably measuring the physical or chemical change of gas or the concentration of a specific gas. It is an object of the present invention to provide a heater device that enables detection and a gas sensor device using the heater device.

The first invention of the present invention that solves the above-mentioned problems is a temperature sensitive resistor comprising a thin film thermally separated from a substrate through a heat insulating part, a thin film heater provided on the surface of the thin film, and a thin film temperature sensor. And a pair of voltage terminals for applying a current to the temperature sensitive resistor, the thin film temperature sensor of the temperature sensitive resistor is disposed in a uniform temperature region at the center of the thin film, The temperature of the thin film is controlled based on information on the temperature sensitive resistor obtained using at least four terminals including the pair of current terminals and a pair of voltage terminals, and the temperature sensitive resistor is a thin film temperature sensor. And a thin film heater formed continuously at both ends of the thin film temperature sensor .

A second invention is the heater device according to the first invention, wherein the thin film heater and the thin film temperature sensor are formed of the same material.

A third invention is the heater device according to any one of the first and second inventions, wherein a thin film heater is disposed around the thin film temperature sensor.

According to a fourth invention, in any one of the first to third inventions, the thin film heater and the thin film temperature sensor are covered with an electrically insulating thin film, and at least a pair of sensitive detection electrodes is provided on the electrically insulating thin film. The heater device is characterized in that a sensitive material thin film is formed.

A fifth invention is the heater device according to the fourth invention, wherein the pair of sensitive detection electrodes are comb-like electrodes.

A sixth invention is the fourth invention, wherein the combination of the thin film heater and the sensitive detection electrode, or the combination of the thin film temperature sensor and the sensitive detection electrode, or the combination of the thin film heater, the thin film temperature sensor and the sensitive detection electrode, The heater device is formed of the same material.

According to a seventh invention, in any one of the fourth to sixth inventions, the sensitive detection electrode is disposed on the thin film temperature sensor with a substantially uniform film thickness through the electrically insulating thin film and the sensitive material thin film. It is in the heater device characterized by this.

According to an eighth invention, in any one of the fourth to seventh inventions, the sensitive detection electrode is a gas sensitive detection electrode, a humidity sensitive detection electrode, an odor sensitive detection electrode, or a biosensitive detection electrode. The heater device is any of the above.

According to a ninth aspect of the present invention, there is provided a heat conduction type gas sensor device for measuring a physical or chemical change of a gas by obtaining a change in heat radiation amount of the thin film from temperature change information of the thin film. The gas sensor device is characterized in that the heater device described in any one of the first to seventh inventions is used and includes a drive circuit, a temperature control circuit, and an arithmetic circuit for driving the heater device.

According to a tenth aspect of the present invention, in the gas sensor device capable of detecting the concentration of the specific gas from the change in electric resistance of the gas sensitive material thin film sensitive to the specific gas from the surrounding gas, the temperature control of the thin film heater is performed. A gas sensor device comprising: a heater circuit according to any one of the fourth to seventh inventions, and a drive circuit, a temperature control circuit, and an arithmetic circuit for driving the heater device.

  The heater device according to the present invention measures the physical or chemical change of the gas from a uniform temperature range by at least the four-terminal method, and detects the concentration of a specific gas from the surrounding gas, so that the output fluctuation is There is an advantage that reduced and highly reliable detection can be obtained.

  Further, since the thin film heater and the thin film temperature sensor are made of the same material, for example, if the thin film heater and the thin film temperature sensor made of a temperature sensitive resistor are formed on the same surface, the work process is simplified and the manufacturing time is reduced. Therefore, the manufacturing cost can be greatly reduced.

  In addition, a thin film heater is disposed around the thin film temperature sensor, and a current flows from the thin film heater so that the thin film heater and the thin film temperature sensor are made of different materials. Since the current flows to both sides, there is an advantage that a short circuit can be formed when a simplified pattern formation and a drive circuit for passing a current are provided.

  Further, the thin film heater and the thin film temperature sensor are covered with an electrically insulating thin film, and a gas sensitive material thin film provided with a gas sensitive detection electrode sensitive to at least a pair of gases is formed on the electrically insulating thin film, By making it possible to detect the change in the electrical characteristics of the gas sensitive material thin film with the pair of gas sensitive detection electrodes in response to the presence of a specific gas, the area of the thin film can be reduced, and the heater device is reduced in consumption. There is an advantage that it can be made electric and can be miniaturized.

  Further, there is an advantage that detection can be performed with high sensitivity by forming a pair of gas sensitive detection electrodes with dense comb-like electrodes.

  The thin film heater and the sensitive detection electrode of the present invention, the thin film temperature sensor and the sensitive detection electrode, or the combination of the thin film heater and the thin film temperature sensor and the sensitive detection electrode are formed of the same material, thereby providing a work process. Has the advantage of simplifying and shortening the manufacturing time.

  In addition, since the sensitive detection electrode is disposed on the thin film temperature sensor with a substantially uniform film thickness through the electrically insulating thin film and the sensitive material thin film, the contact area is increased, which is effective for improving the sensitivity. . Furthermore, since the thin film heater that flows a large current to generate heat can be reduced, there is an advantage that the current is also reduced.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a heater device of the present invention and a gas sensor device using the same will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  The configuration of the heater device according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic plan view of an embodiment of the heater device according to the present invention, and FIG. 2 is a schematic cross-sectional view taken along line XX of FIG. As shown in FIGS. 1 and 2, in the heater device according to the present invention, the silicon substrate 1 is a substrate having a (100) plane orientation, and the thin film 10 is formed on a cavity 80 provided on the substrate. . The thin film 10 is formed by forming a temperature sensitive resistor 22 including a heat resistant thin film 40 and a thin film temperature sensor 21 on which thin film heaters 20-1 and 20-2 are arranged in series on both ends. The temperature sensitive resistor 22 composed of the heaters 20-1 and 20-2 and the thin film temperature sensor 21 is covered with an electrically insulating thin film 50.

  On the silicon substrate 1, a heat-resistant thin film 40 made of tantalum oxide, thin film heaters 20-1, 20-2 or thin film temperature sensor 21 made of platinum are deposited by sputtering, and the thin film heaters 20-1, 20-2 are deposited. Alternatively, the patterning of the thin film temperature sensor 21 is partially removed by photolithography and dry etching. Thereafter, similarly, an electrically insulating thin film 50 made of tantalum oxide is deposited by sputtering. Thereafter, various layers are removed by photolithography and dry etching, and the silicon substrate 1 is removed by etching the thin film 10 with a mask and a TMAH (tetramethylammonium hydroxide) solution, thereby forming a micro bridge structure. The heater device has a (structure having a bridging portion).

  The heater device according to the present example is a temperature sensitive device including a thin film 10 thermally separated from the substrate 1 through a cavity 80, and a thin film heater 20 and a thin film temperature sensor 21 provided on the surface of the thin film 10. A resistor 22; current terminals 101-1 and 101-2 for applying a current to the temperature sensitive resistor 22; and at least a pair of voltage terminals 102-1 and 102-2 for measuring a voltage of the temperature sensitive resistor 22. And the temperature of the thin film is controlled based on the information of the temperature-sensitive resistor obtained by the four-terminal method.

  In this embodiment, the thin film temperature sensor 21 of the temperature sensitive resistor 22 is disposed at the center of the thin film 10, and the temperature near the center of the thin film is accurately measured by the four-terminal method. Thus, the temperature of the thin film heater 20 is controlled with higher accuracy.

  According to the present embodiment, the temperature of the temperature sensitive resistor 22 is controlled based on the information of the temperature sensitive resistor 22 obtained using at least four terminals. It is possible to accurately measure only the temperature in a specific region.

  As a driving method of the heater device according to the first embodiment, bonding pads 201-1 and 201-2 of the thin film heater 20 are provided at the ends of the current terminals 101-1 and 101-2 and the voltage terminals 102-1 and 102-2. And the bonding pads 202-1 and 202-2 of the thin film temperature sensor 21 are formed, and when the current is applied to the bonding pads 201-1 and 201-2 of the thin film heater 20, the thin film heater 20 generates heat. At the same time, the thin film temperature sensor 21 also generates heat.

  Here, although the temperature of the thin film heater 20 changes from the state of the ambient atmosphere, since heat is radiated to the vicinity of the bridging portion 70, a temperature difference occurs between the central portion and the outer peripheral portion of the thin film 10. However, as in this embodiment, the resistance value (voltage) in the thin film temperature sensor 21 that is a uniform temperature region in the center of the thin film 10 is the four-terminal method, that is, the current and voltage that are supplied to the current terminals 101-1 and 101-2. By detecting using the terminals 102-1 and 102-2, high-accuracy measurement is possible.

  Furthermore, in the presence of non-uniform temperature distribution of the thin film 10, not only the average temperature but also the temperature at the center, which is the region with the highest temperature, is partially detected, thereby further improving sensitivity and reliability. Temperature change information due to a highly stable resistance value change can be obtained.

  In order to increase the sensitivity of the thin film temperature sensor 21, the thin film temperature sensor 21 may also be used as the thin film heater 20, and measurement may be performed by passing a large current, which is advantageous for improving the sensitivity. is there.

Further, as shown in FIG. 3, the thin film temperature sensor 21 is formed in a zigzag pattern, and thin film heaters 20-1 and 20-2 are arranged in series at both ends of the thin film sensor, and a plurality of thin film temperature sensors 21 are arranged on the thin film temperature sensor 21. A terminal may be provided, and measurement may be performed using a plurality of terminals of four terminals or more.
At this time, by measuring the resistance value (output voltage) between the voltage terminals V _{11 and} V ₁₂ or the voltage terminals V _{21 and} V ₂₂ provided in a part of the thin film heaters 20-1 and 20-2, It can be used as a temperature sensor in this region of the temperature resistor 22. Since a large current flows as a heater, the output voltage increases even if the interval between the voltage terminals is narrow, and resistance detection, that is, temperature detection can be performed with high sensitivity. In the present embodiment, terminals for measuring V ₂₁ -V ₂₂ are omitted.

  In addition to using the same material for the thin film heater 20 and the thin film temperature sensor 21, both the thin film heater 21 and the thin film temperature sensor 21 can be formed by using different materials or thickening the temperature sensor wiring. Resistance and temperature can be changed.

  In this embodiment, the microbridge structure is formed by forming the bridging portion 70. However, the present invention is not limited to this, and a cantilever structure, a diaphragm structure, or a sacrificial layer having a cavity 80 is used. Various configurations such as a floating structure floating on the substrate 1 may be employed.

  In this embodiment, since the thin film heater 20 and the thin film temperature sensor 21 are made of the temperature sensitive resistor 22, it is optimal to use a platinum film, which simplifies the work process and shortens the manufacturing time. Cost can be reduced.

  Alternatively, the thin film temperature sensor 21 may be separated and surrounded by the thin film heater 20 at a uniform temperature near the center of the air bridge structure.

  The thin film temperature sensor 21 may be a thermistor, and the thin film heater 20 may be made of a material such as gold, nickel, copper, or the like, and may be appropriately changed depending on the application.

  Here, when the heat-resistant thin film 40 and the electrically insulating thin film 50 are made of the same material as that of tantalum oxide, the workability such as etching becomes easier, and the manufacturing cost can be reduced.

  Moreover, since the thin film 10 becomes high temperature of 200-500 degreeC, it is desirable to comprise with the silicon oxide, titanium oxide, aluminum oxide etc. which are excellent in heat resistance and electrical insulation.

  In this embodiment, the voltage terminals 102-1 and 102-2 detected by the thin film temperature sensor 21 are paired. However, in order to improve stability and reliability, a plurality of pairs are provided at the center of the thin film 10. You may make it comprise a terminal.

A second embodiment of the present invention will be described with reference to FIG.
Example 2 is based on the heater device of Example 1 described above. Gas sensitive detection electrodes 30-1 and 30-2 and a gas sensitive material thin film 60 are formed on the heater device, and the concentration of a specific gas is increased. It has a structure that can be detected. In addition, about the member same as Example 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

The configuration of the heater device according to the present invention will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view of another embodiment relating to the heater device of the present invention.
As shown in FIG. 4, in the heater device according to this example, the silicon substrate 1 is a substrate having a (100) plane orientation, and a thin film having an insulating heat-resistant thin film 40 on a cavity provided on the substrate. The thin film 10 includes a heat-resistant thin film 40 and a thin film temperature sensor 21 arranged in series between the thin film heater 20-1 and the thin film heater 20-2 in a zigzag pattern thereon. The thin film heater 20 and the thin film temperature sensor 21 are covered with an electrically insulating thin film 50.

  The configuration in the temperature detection of the temperature uniform region by the four-terminal method is the same as that of the first embodiment described above, and the gas-sensitive material thin film 50 is covered with the gas-sensitive material thin film 60, and the gas-sensitive material composed of a pair of comb teeth is formed thereon. Detection electrodes 30-1 and 30-2 are formed.

  Here, the gas sensitive detection electrodes 30-1 and 30-2 are arranged on the thin film temperature sensor 21 with a substantially uniform film thickness through the electrically insulating thin film 50 and the gas sensitive thin film 60, and the thin film temperature sensor 21. The cross-sectional shape of the gas sensitive detection electrodes 30-1 and 30-2 is also a shape corresponding to the shape of the thin film temperature sensor 21 so that the shape based on the cross-sectional structure is reflected.

The silicon substrate 1 is patterned by heat-resistant thin film 40 made of tantalum oxide film, thin film heater 20 or thin film temperature sensor 21 made of platinum film, thin film heater 20 or thin film temperature sensor 21 by photolithography and dry etching. To partially remove.
Thereafter, an electrically insulating thin film 50 made of a tantalum oxide film, a gas sensitive material thin film 60 made of a tin oxide film, and gas sensitive detection electrodes 30-1 and 30-2 made of a platinum film are similarly deposited by sputtering. The patterning of the sensitive detection electrodes 30-1 and 30-2 is partially removed by photolithography and dry etching.

  Thereafter, various layers are removed by dry etching with photolithography, and the thin film 10 is removed by etching the silicon substrate 1 with a mask and a TMAH (tetramethylammonium hydroxide) solution to form a micro bridge 80. It has a structure.

In the heater device driving method according to the second embodiment, as in the first embodiment, although not illustrated, the current terminals 101-1 and 101-2, the voltage terminals 102-1 and 102-2, and the ends of the gas sensitive detection electrode wirings. Are formed with bonding pads 201-1 and 201-2 of the thin film heaters 20-1 and 20-2 and bonding pads 202-1 and 202-2 of the thin film temperature sensor 21, and although not shown, gas sensitive detection is performed. Bonding pads for the electrodes 30-1 and 30-2 are formed.
When the thin film heaters 20-1 and 20-2 generate heat by applying current to the bonding pads 201-1 and 201-2 of the thin film heaters 20-1 and 20-2, similarly, the thin film temperature sensor 21 Fever is generated. Although the thin film heaters 20-1 and 20-2 change in temperature from the ambient atmosphere due to electric resistance, heat is radiated to the vicinity of the bridging portion 70.

  From this, the resistance value (voltage) in the thin film temperature sensor 21, which is a uniform temperature region at the center of the thin film 10, is detected by the four-terminal method, that is, the current flowing through the current terminals 101-1 and 101-2 and the voltage terminal 102-1. , 102-2 can be measured with high accuracy, and the thin film 10 has a non-uniform temperature distribution. By detecting a part of the temperature, the sensitivity becomes high, and the temperature change information by the change of the resistance value with high reliability and stability can be obtained.

  Based on the temperature information, the uniform temperature region at the center of the thin film 10 is controlled to 200 to 500 ° C. by the heat generated by the thin film heater 20. The gas sensitive material thin film 60 detects the resistance value (voltage) of the gas sensitive material thin film 60 by the gas sensitive detection electrodes 30-1 and 30-2 including a pair of comb teeth according to the controlled temperature. Change in concentration can be detected.

  In FIG. 5, the gas sensitive detection electrodes 30-1 and 30-2 are arranged with a substantially uniform film thickness on the thin film temperature sensor 21 via the electrically insulating thin film 50 and the gas sensitive material thin film 60. In the embodiment, the cross-sectional shapes of the gas sensitive detection electrodes 30-1 and 30-2 are also formed in an uneven shape so that the uneven shape based on the cross-sectional structure of the thin film temperature sensor 21 formed in a zigzag shape is reflected. By forming the electrodes in an uneven shape in this way, the surface area of the gas sensitive detection electrodes 30-1 and 30-2 that form a pair can be increased, and information with a larger output than that of the planar shape can be obtained.

  Thus, in order to provide the gas sensitive detection electrodes 30-1 and 30-2 in the uniform temperature region at the center of the thin film 10, the range formed by the gas sensitive detection electrodes 30-1 and 30-2 is as small as possible. This is more advantageous, and the contact area between the pair of gas sensitive detection electrodes 30-1 and 30-2 is increased by making the uneven shape, which is effective in improving the sensitivity.

  In addition, since the thin film heater 20 through which a large current flows to generate heat can be reduced, there is an advantage that the current is also reduced. In this way, an extremely small heater device with low consumption can be provided.

  Further, since the gas sensitive detection electrodes 30-1 and 30-2 are formed in the uniform temperature region at the center of the thin film 10, highly reliable information without temperature unevenness can be obtained.

  In this embodiment, the gas sensitive material thin film 60 is made of tin oxide. However, the gas sensitive film may be made of zinc oxide, nickel oxide, copper oxide, chromium oxide or the like, or their main component. As a film forming method, a vacuum deposition method, a plasma CVD method, a screen printing method, or the like may be used.

  In Example 2, the gas sensitive detection electrodes 30-1 and 30-2 each having a pair of comb teeth are formed on the gas sensitive material thin film 60. However, the gas sensitivity having a pair of comb teeth is formed. The gas sensitive material thin film 60 may be formed on the detection electrodes 30-1 and 30-2.

In this embodiment, the structure and materials of the thin film heater 20 and the thin film temperature sensor 21 similar to those in the first embodiment are desirable. In addition, the thin film heater 20, the thin film temperature sensor 21, and the gas sensitive detection electrodes 30-1 and 30-2 can simplify the work process and can reduce the manufacturing time if they are limited to platinum or the like.

  Further, in the material, the sensitive detection electrodes 30-1 and 30-2 may be different depending on the application if they constitute gold, nickel, and copper.

  In the above-described embodiments, the gas sensitive detection electrode is exemplified as the sensitive detection electrode. However, the present invention is not limited to this. For example, the humidity sensitive detection electrode, the odor sensitive detection electrode, or the bio Sensing according to the intended application can be performed using various electrodes such as a sensitive detection electrode.

FIG. 6 is a block diagram showing an outline of the configuration of the gas sensor device equipped with the heater device of the present invention.
In this embodiment, the heater device 1001 according to the embodiment is a case where at least a part of a drive circuit is integrated on a semiconductor chip having a temperature detection portion related to the thin film 10, and includes a power supply unit 1002, a reference temperature, and the like. The peripheral devices necessary for the correction circuit 1003, the temperature control circuit 1004, the arithmetic circuit 1005, and the output display unit 1006 are mounted, and the heat radiation amount change of the thin film 10 is obtained from the temperature change information of the thin film 10, and the gas It shows the case where it implements as a heat-conduction type gas sensor apparatus which measures the physical or chemical change of this.

  In addition, the concentration of the specific gas can be detected from the change in electric resistance of the gas sensitive material thin film 60 that is sensitive to the specific gas from the surrounding gas. Note that the peripheral devices described above can be implemented by conventional known techniques.

  The heater device of the present invention and the gas sensor device using the heater device are not limited to the present embodiment, and various modifications may be made while the gist, operation, and effect of the present invention are the same.

  Further, in the present invention, by measuring using at least four terminals or more, the temperature is partially detected from the region near the central portion where the temperature is the highest among the uniform temperature regions of the thin film floating in the air. Based on this information, it can measure the physical or chemical change of gas, and can detect the concentration of a specific gas from the surrounding gas with high reliability and reliability. Can be provided. Therefore, the heat device of the present invention can be mass-produced easily and uniformly by using the micro electro-mechanical system (MEMS) technology that combines the latest semiconductor microfabrication technology and integration technology. It will be cheaper.

  The heater device of the present invention can be used as various sensors such as a temperature sensor, a humidity sensor, a gas sensor, an odor sensor, and a biosensor. For example, a gas sensor device using the heater device can be used for an automotive engine coolant temperature, an intake air temperature, Various areas such as exhaust detection, control for operating the engine in the optimum state, alarms, engine air heat ratio control, disaster prevention and safety, process control, environmental control, energy saving, intelligent appliances, etc. Development can be achieved.

1 is a schematic plan view relating to a heater device according to Example 1. FIG. FIG. 2 is a schematic cross-sectional view taken along line XX in FIG. 1. It is the plane schematic of one Example regarding the other heater device concerning Example 1. FIG. It is a cross-sectional schematic regarding the heater device concerning Example 2. FIG. It is a perspective schematic diagram explaining the arrangement | positioning relationship of the thin film heater or thin film temperature sensor concerning Example 2, and the temperature detection electrode. It is a block diagram which shows the outline of a structure of a gas sensor apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 10 Thin film 20 Thin film heater 21 Thin film temperature sensor 22 Temperature sensitive resistor 30-1, 30-2 Gas sensitive detection electrode 40 Heat resistant thin film 50 Electrical insulating thin film 60 Gas sensitive material thin film 70 Cross-linking part 80 Cavity part 101- DESCRIPTION OF SYMBOLS 1, 101-2 Current terminal 102-1 and 102-2 Voltage terminal 201-1 and 201-2 Thin film heater 20 bonding pad 202-1 and 202-2 Thin film temperature sensor 21 bonding pad

Claims (10)

A thin film thermally separated from the substrate through a heat insulating part;
A temperature sensitive resistor comprising a thin film heater and a thin film temperature sensor provided on the surface of the thin film;
A pair of current terminals for applying a current to the temperature sensitive resistor;
Comprising at least a pair of voltage terminals for measuring the voltage of the temperature sensitive resistor,
The thin film temperature sensor of the temperature sensitive resistor is disposed in a uniform temperature region at the center of the thin film, and the temperature sensitive value obtained using at least four terminals including the pair of current terminals and the pair of voltage terminals. While controlling the temperature of the thin film based on the information of the resistor ,
A heater device, wherein the temperature sensitive resistor comprises a thin film temperature sensor and a thin film heater formed continuously at both ends of the thin film temperature sensor . Oite to claim 1,
A heater device, wherein the thin film heater and the thin film temperature sensor are formed of the same material. In claim 1 or 2 ,
A heater device comprising a thin film heater disposed around the thin film temperature sensor. In any one of Claims 1 thru | or 3 ,
A heater device comprising: a thin film heater and a thin film temperature sensor covered with an electrically insulating thin film; and a sensitive material thin film provided with at least a pair of sensitive detection electrodes on the electrically insulating thin film. . In claim 4 ,
A heater device, wherein the pair of sensitive detection electrodes are comb-like electrodes. In claim 4 ,
A combination of a thin film heater and a sensitive detection electrode, or a combination of a thin film temperature sensor and a sensitive detection electrode, or a combination of a thin film heater, a thin film temperature sensor and a sensitive detection electrode.
A heater device formed of the same material. In any one of Claims 4 thru | or 6 ,
A heater device, wherein the sensitive detection electrode is disposed on a thin film temperature sensor with a substantially uniform film thickness through an electrically insulating thin film and a sensitive material thin film. In any one of Claims 4 thru | or 7 ,
The heater device, wherein the sensitive detection electrode is any one of a gas sensitive detection electrode, a humidity sensitive detection electrode, an odor sensitive detection electrode, and a biosensitive detection electrode. In a heat conduction type gas sensor device for measuring a physical or chemical change of a gas by obtaining a change in heat radiation amount of the thin film from temperature change information of the thin film,
A gas characterized in that the temperature control of the thin film heater is performed using the heater device according to any one of claims 1 to 7 and includes a drive circuit, a temperature control circuit, and an arithmetic circuit for driving the heater device. Sensor device. In the gas sensor device that can detect the concentration of the specific gas from the electric resistance change of the gas sensitive material thin film that is sensitive to the specific gas from the surrounding gas,
The temperature control of the thin film heater is performed using the heater device according to any one of claims 4 to 7 , and includes a drive circuit, a temperature control circuit, and an arithmetic circuit for driving the heater device. Gas sensor device.

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